Sensory Evaluation Principles Flashcards

A product development team wants to create a detailed sensory 'fingerprint' of their new artisanal ketchup to understand the intensity of specific attributes like 'smoky aroma,' 'vinegar tang,' and 'cooked tomato flavor.' Which sensory evaluation method is most suitable for this objective?

Answer: Quantitative Descriptive Analysis (QDA)

Quantitative Descriptive Analysis (QDA) is the correct method because it uses a trained panel to identify, define, and quantify the intensity of specific sensory attributes of a product. This process generates a detailed sensory profile, or 'fingerprint.' Affective tests measure liking, while Triangle and Duo-Trio tests are discrimination tests used only to determine if a perceptible difference exists between samples.

A research chef is conducting a large-scale consumer taste test for three new frozen pizza prototypes to determine which one consumers like the most. Which type of sensory test and scale is most appropriate for measuring consumer preference and acceptance?

Answer: Affective Test with a 9-point Hedonic scale

An Affective Test is used to measure subjective responses like preference and liking. The 9-point Hedonic scale is the industry standard for quantifying consumer acceptance, ranging from 'dislike extremely' to 'like extremely'. Discrimination tests determine if a difference exists, descriptive tests profile attributes with trained panelists, and threshold tests find detection limits.

To minimize psychological bias and ensure the validity of sensory panel results, which of the following practices is most critical?

Answer: Randomizing the presentation order of samples and using three-digit codes

Randomizing the sample order prevents first-sample bias, while using non-descriptive three-digit codes (e.g., 417, 832) prevents panelists from being influenced by any perceived order or identity of the samples. Providing detailed product information or encouraging group discussion would introduce significant bias. While using category users can be important for some tests, it doesn't inherently minimize psychological bias during the test itself.

A quality assurance team needs to determine the lowest concentration of a specific off-flavor (e.g., geosmin in water) that can be reliably detected by their expert panelists. What is this minimum detectable level called?

Answer: Absolute Threshold

The Absolute Threshold is defined as the lowest level or minimum intensity of a stimulus (like an aroma or taste) that an organism can detect. The Just Noticeable Difference (JND) is the smallest change in intensity that can be perceived. The Terminal Threshold is the point at which an increase in stimulus intensity is no longer perceived. 'Hedonic Limit' is not a standard sensory term.

A soup company has reformulated its classic chicken noodle soup using a new, cost-effective yeast extract. The goal is to ensure that consumers cannot perceive a difference between the original and the reformulated product. Which sensory test is specifically designed for this 'is there a difference?' question?

Answer: Discrimination Test

Discrimination tests (such as the Triangle or Duo-Trio test) are specifically designed to determine whether a perceptible sensory difference exists between two or more products. Affective tests measure liking, Descriptive tests profile attributes, and Ranking tests order samples based on a specific attribute or preference.

During a Descriptive Analysis panel for a new granola bar, the panel leader provides the panelists with physical examples of different textures (e.g., sand for 'gritty', raisins for 'chewy') to ensure all panelists are using the attribute terms consistently. What are these physical examples called?

Answer: References

In descriptive analysis, references are used to define and anchor the endpoints or specific points on an intensity scale for a sensory attribute. This ensures all trained panelists have the same internal calibration for terms like 'gritty' or 'chewy', improving the reliability and reproducibility of the data. While a 'gold standard' is a perfect example of the final product, 'references' are used to define individual attributes.